Polemonium pauciflorum
Polygala calcarea
Chalk Milkwort
Polygala fruticosa
Feather Dusters
Polygala paniculata
Root Beer Plant
Polygala serpyllifolia
Heath Milkwort
Polygala vulgaris
Common Milkwort
Polygonatum multiflorum
Solomon's-seal
Polygonatum odoratum
Angular Solomon's-seal
Polygonatum verticillatum
Whorled Solomon's-seal
Polygonatum x hybridum
Garden Solomon's-seal
Polygonum arenastrum
Equal-leaved Knotgrass
Polygonum aviculare
Knotgrass
Polygonum oxyspermum
Ray's Knotgrass
Polyscias fruticosa
Ming Aralia
Polyscias guilfoylei
Geranium Aralia
Pontederia crassipes
Water Hyacinth
Populus nigra
Black-poplar
Populus tremula
Aspen
Populus x canadensis
Hybrid Black-poplar
Populus x canescens
Grey Poplar
Portulaca grandiflora
Rose Moss
Portulaca oleracea
Common Purslane
Potamogeton coloratus
Fen Pondweed
Potamogeton crispus
Curled Pondweed